Changes

This is the most common type of zonal necrosis and occurs mainly due to the fact that hepatocytes in this central zone are furthest away from the incoming blood supply. They are therefore more susceptible to hypoxia. Additionally, they contain the greatest concentration of cytochrome p450 enzymes that metabolise substances into more reactive metabolites capable of killing the hepatocytes. Therefore toxic insults and conditions leasing to hypoxia commonly produce this pattern of necrosis. Some viral conditions, however, also result in centrilobular necrosis, such as '''[[Infectious Canine Hepatitis]] (ICH)'''. This is a highly infectious disease of young dogs caused by canine adenovirus-1. It is now rare in the UK and US due to effective vaccination protocols.

This is the most common type of zonal necrosis and occurs mainly due to the fact that hepatocytes in this central zone are furthest away from the incoming blood supply. They are therefore more susceptible to hypoxia. Additionally, they contain the greatest concentration of cytochrome p450 enzymes that metabolise substances into more reactive metabolites capable of killing the hepatocytes. Therefore toxic insults and conditions leasing to hypoxia commonly produce this pattern of necrosis. Some viral conditions, however, also result in centrilobular necrosis, such as '''[[Infectious Canine Hepatitis]] (ICH)'''. This is a highly infectious disease of young dogs caused by canine adenovirus-1. It is now rare in the UK and US due to effective vaccination protocols.

===Midzonal===

'''Midzonal'''<br>

Midzonal necrosis is rare and is mainly seen in pigs with aflatoxicosis. It is also seen in humans suffering from 'Yellow Fever'.

This pattern of necrosis is rare in animals although is mainly seen in horses and pigs with aflatoxicosis. It is also seen in people suffering from 'Yellow Fever'.

======Periportal (Centroacinar)======

'''Periportal (Centroacinar)'''<br>

Centroacinar necrosis is also rare. This has been seen in cases of phosphorous poisoning.

This is another uncommon pattern of necrosis that only involves a region around the central vein. It is caused by direct-acting hepatotoxins, and is seen in cases of phosphorus poisoning.

 

Regardless of the zone affected, grossly the liver is pale, friable, slightly enlargedwith rounded edges, and has an enhanced lobular pattern.

=== Massive Necrosis ===

=== Massive Necrosis ===